The invention relates in a general manner to the field of cabinets and enclosures, notably that of cabinets and enclosures used for housing electrical and/or electronic switchgear.
Its object is more particularly to achieve a corner junction for a cabinet or enclosure of this kind, enabling trihedral assembly of profiles and/or uprights, and a cabinet of appreciably parallelepipedic shape comprising a corner junction of this kind at each of its eight apexes.
Hereinafter, the term "cabinet" will designate both a cabinet or an enclosure.
In state-of-the-art manner, for example according to the documents FR-A-2,681,403, EP-A-402,276 and EP-A-144,995, a cabinet of this kind is made up of a parallelepipedic framework achieved with twelve identical hollow profile sections, assembled by means of corner junctions, and a covering dressing made up of panels. The corner junction is formed by a tripod, which may have a monobloc structure, whose three feet fit respectively inside the three corresponding profile sections.
A junction of this kind, which is at first sight very attractive, does however present several drawbacks in terms of cost, mechanical strength, flexibility of use, and convenience when fitting the electrical switchgear inside such a cabinet. First of all, the tripod is fragile since it is subjected to large mechanical stresses; it is also relatively complex due to its shape and consequently costly to manufacture. Moreover, the rigidity of this type of junction is not always satisfactory, as it depends greatly on the internal dimensions of the profile. Consequently, to obtain a good rigidity, the manufacturing tolerances of the profile have to be reduced, thereby inducing extra expense as far as profile turning is concerned. Moreover, as the feet of the tripod fit into the profile sections, it is impossible to disassemble one or the other of the vertical uprights of the framework once the four vertical covering panels of the cabinet have been removed, without having at least partially removed the roof of the cabinet beforehand, at least without deformation of the framework which is liable in turn to deform the profiles at the level of the corner junctions and thus reduce the strength of the framework. Finally, assembly by tripod is also very costly in terms of man-hours, as it requires tightening/untightening of a large number of screws. This results in the person in charge of fitting the electrical switchgear inside the cabinet either wasting time in partially disassembling the roof to remove an upright of the framework in order to achieve a more convenient access to the inside of the cabinet, or accepting the inconvenience resulting from the presence of the four vertical uprights of the framework, which also represents a waste of time.